Borderlands Granular, £2.49/$3.99

Compatibility: iPad (requires iOS 5.0 or later)

Borderlands Granular is a very cool little granular synthesis instrument for iPad.

It utilises the devices touchscreen allowing the user to move and manipulate a cluster of pulsing grains over a backdrop of audio files that can also be dragged, morphed and rearranged. The results create some impressive, evolving atmospherics.